Sabrina Carpente r's birthday is a national holiday in my house. I smile at my Carpenter-marked calendar every May 11, because I know an on-brand vintage birthday dress from my favorite pop star will hit Instagram. Yesterday, she celebrated her 27th trip around the sun in her third vintage birthday dress in a row. I already can't wait for 28. The backdrop behind Carpenter's b-day IG post was, once again, unidentifiable. But unlike the fireplace, bookcase, and sconces, I'd recognize her dress's purple fringe anywhere. She and stylist Jared Ellner put their archival-adoring brains together and tracked down a vintage Dolce & Gabbana dress . It's unclear when the satin slip's tiered, asymmetrical fringe first swished down the runway. But the oversize rosette atop the plunge, tasseled neckline suggested it was sometime in the '90s. The Grammy winner's exact calf-grazing number just sold-out at Canada's VSP Consignment , perhaps thanks to Carpenter and Ellner.…